1. Field of the Invention
The present invention relates to a microscope objective, and more particularly relates to a microscope objective that uses visible light and ultraviolet light.
2. Description of the Related Art
In recent years, specimens have not only been observed by illumination with visible light in the wavelength region of approximately 400 to 750 nm, but they have also been observed and processed by illumination with light of short wavelengths, such as ultraviolet light.
In viewing specimens through a microscope it is important to correct chromatic aberration simultaneously for both visible light and ultraviolet light in an objective of a microscope that observes a specimen using visible light and ultraviolet light in combination. This correction is called achromatism. However, there is a limited number of glass materials available that satisfy the achromatism condition for visible light and ultraviolet light. Consequently, even though a so-called parfocal length is increased to achieve achromatism, there is a problem in that chromatic aberration cannot be sufficiently corrected.